<?php
/**
 * Skyline :: Patterns & component framework
 * Copyright 2010-2011 Ian Unruh (Xerof3ar)
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
namespace Skyline\Structure;

use Countable;
use IteratorAggregate;

/**
 * A container represents any structure that contains a number of
 * elements. Containers are countable, iterable, and can be cleared
 * of any elements.
 * 
 * @author Ian Unruh (Xerof3ar) <ianunruh@gmail.com>
 * @since Class avaliable since release 1.0
 */
interface ContainerInterface extends Countable, IteratorAggregate
{
	/**
	 * Clears this container of all its elements
	 * @return void
	 */
	public function clear();
	
	/**
	 * Returns true if this container is empty
	 * @return bool
	 */
	public function isEmpty();
}